To establish the phylogenetic relationships of Massarina species by comparison of the nucleotide sequences of evolutionary conserved regions of their mitochondrial and ribosomal DNA; to establish the phylogenetic relationships of Massarina species to ot her families by comparison of the nucleotide sequences of evolutionary conserved regions of their mitochondrial and ribosomal DNA; to equate the phylogenetic relationships derived from DNA sequencing with our observations derived from morphological and ultrastructural studies; to establish the evolutionary phylogeny of Massarina species including freshwater, marine and terrestrial taxa, by comparison of the nucleotide sequences of evolutionary conserved regions of their mitochondrial and ribosomal DNA ; to examine the character coding and phylogenetic analysis of morphological and ultrastructural characteristics.